Apparatus for mixing particulate materials

ABSTRACT

Apparatus for receiving two or more streams of powdered or granular materials includes means to stir the received materials while such materials are vigorously vibrated and to discharge the mixed materials at a rate which is equal to the inlet rate.

United States Patent [72] Inventor Eugene A. Wahl '294 Forest Ave., GlenRidge, NJ. 07028 [2]] Appl. No. 811,798 [22] Filed Apr. 1,1969 [45]Patented Aug. 24,1971

[54] APPARATUS FOR MIXING PARTICULATE MATERIALS 5 Claims, 2 DrawingFigs.

[52] 11.8. C1 259/2, 259/72 [51] Int.Cl B0lfll/00 [50] Field of Search259/78, 93, 174, 2,13,17, 35, 56, 59,10, 9,178, 92, 94, 72, D16. 41, 12,29, 54

[56] References Cited UNITED STATES PATENTS 2,801,237 7/1957 Clevy et al259/93 X 3,347,528 10/1967 List et al. 259/2 2,210,366 8/1940 Godfrey etal. 259/109 X 2,365,897 12/1944 Morgan 259/93 FOREIGN PATENTS 586,27311/1959 Canada 259/D1G. 44 145,441 5/1962 U.S.S.R. 259/D1G. 41

OTHER REFERENCES German Printed Application Ser. No. 4081 lVc/l2e, Date:2/56, Applicant: K. Nittka et 211:, Class; 259/Vibrators- Meeh. DigestPrimary Examiner-Walter A. Scheel Assistant Examiner-Alan 1. CantorAttorney-Rudolph J. Jurick ABSTRACT: Apparatus for receiving two or morestreams of powdered or granular materials includes means to stir thereceived materials while such materials are vigorously vibrated and todischarge the mixed materials at a rate which is equal to the inletrate.

PATENTEU AUB24|97| 3501; 359

EUGENE A. WAHL INVENTOR.

BY 7 I APPARATUS FOR MIXING PARTICULATE MATERIALS BACKGROUND OF THEINVENTION Apparatus is available for receiving powdered or granularmaterial from a supply hopper and discharging the material at apredetermined, constant feedrate. In many processes, it also isnecessary to provide an intimate mixture of two or more materials inpredetermined proportions and as a continuous stream. In general, priormixing apparatus is bulky and expensive, is not easily disassembled forcleaning, and does not provide an intimate and rapid blending ofthematerials coupled with gentle action. Also, previous continuousmixers are of the positive displacement type wherein discharging of thematerials is effected by a rotating screw or like device which governsthe material retention or mixing time.

SUMMARY OF THE INVENTION Continuous streams of materials to be mixed aredirected into one end of an elongated trough containing a rotatingpaddle wheel arrangement, said trough being vibrated to reduce thecontainer materials from a solid state to a fluid state, in

I which condition the materials are more readily miscible. Due

to the fluid character of the material, the translation of the materialfrom the inlet end of the trough to the outlet end thereof takes placeby reason of the difference in the static head of the material at thetrough ends, whereby the discharge rate of the apparatus always balancesthe inlet rate.

An object of this invention is the provision of improved apparatus forintimately mixing powdered or granular materials and discharging themixed materials at a rate governed only by that at which the materialsare supplied to the apparatus, thereby providing for maximum retentionor mixing time.

An object of this invention is the provision of apparatus for receivingcontinuous streams of different materials, simultaneously'vibrating andstirring the materials, and continuously discharging the mixed materialsat a rate which at all times balances the rate at which materials arebeing supplied to the apparatus.

An object of this invention is the provision of mixing apparatus havinga tubular member .provided with a material inlet and a material outlet,a rotatable paddle wheel arrangement within the tubular member, andmeans for vibrating the tubular member and paddle wheel arrangement toimpart a fluidlike characteristic to the material contained within thetrough.

The above-stated and other objects and advantages of the invention willbecome apparent from the following description when taken with theaccompanying drawings. It will be understood, however, that the drawingsare for purposes of illustration and are not to be construed as definingthe scope or limits of the invention, reference being had for the latterpurpose to the claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein like referencenumerals denote like parts in the several views:

FIG. 1 is a side elevational view of mixing apparatus made in accordancewith this invention, with parts broken away; and

FIG. 2 is a cross-sectional view taken along line lI-ll of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, theapparatus is supported on a bonded at each end as by vulcanizing. Suchisolators support,

an I-beam 16, said beam and isolators being secured to the brackets bymeans of bolts and nuts. Thus, the I-beam and the brackets are heldapart by the isolators and can move parallel to one another within thestretch limits of the rubber. A circular clamp 17, secured to the motorhousing, has welded thereto a plate 18, which plate also is welded tothe I-beam. The drive shaft of the motor is mechanically coupled to ashaft 19 by means of pulleys and a belt 20, said shaft 19 beingrotatable in bearings 21, carried by the I-beam, and said shaft havingsecured thereto spaced, eccentric weights 22 and 23. Upon energizationof the motor, the rotating weights impart vigorous vibrations to theI-beam.

The other end of the I-beam is welded, or otherwise secured to the topwall of a housing 23, which housing is open at the bottom and has aninverted, U-shaped, cross-sectional configuration. An elongated trough24, having a semicircular bottom portion, is welded to a bracket 25which is removably secured to the housing 23 by means of the bolts 26and nuts 27'. The housing 23 is spaced from the base 10 and is supportedtherefrom by a vibration-isolating mounting comprising a metal arm 27having rubber bushings 28 and 29 pressed into the circular ends thereof.Spaced rods 30 and 31 are force-fitted through the rubber bushings andhave ends passing through aligned holes formed in the associatedmounting brackets 32 and 33, the upper mounting bracket 32 being securedto the housing 23 and the lower bracket 33 being secured to the base 10.This arrangement permits unrestricted vibration of the housing 23 in ahorizontal plane while minimizing the transmission of vibrations to thebase 10.

The material mixing function is performed by paddle wheels comprisingfour bars 35-38 welded to the end portions of the spiders 39-42 whichare secured to the shaft 43 rotatable in bearings carried by the endwalls of the trough 24. This shaft is mechanically coupled to the driveshaft of motor 44 by means of pulleys and the belt 45, said motor beingbolted to the base 10. The upper end of the trough is closed by a cover46 provided with an inlet opening 47. A circular segment opening 48,formed in the front wall of the trough 24, constitutes the dischargeopening of the apparatus.

The powdered or granular materials are supplied to the trough throughthe inlet opening 47, each material being discharged from a conventionalmaterial feeder at a predetermined, constant flowrate. The rotatingpaddle wheel stirs the received materials while they are vigorouslyvibrated, such vibration having the effect of converting the materialsto a pseudofluid state, in which state the materials are more readilymiscible. The function of the straight bars of the paddle wheel is tolift and drop the materials at substantially right angles to the mixershaft 43. Translation of the material toward the discharge opening 48occurs by reason of its fluidization and the difference in the statichead of the material at the inlet and outlet ends of the trough 24. Dueto the fluidlike character of the material, induced by vibration, thestatic head differential serves to maintain a continuous flow of themixed materials out of the discharge opening. Consequently, the mixingapparatus is self-adjusting with respect to the fiowrate, that is, thedischarge rate of the apparatus always balances the input rate, whilemaintaining maximum material-retention time in the mixer.

The described apparatus provides an intimate mixing of powdered orgranular materials combined with gentle action. The mixing action israpid, permitting operation of the apparatus at high flowrates. Also,the apparatus is easily disassembled for cleaning, the latter featurebeing an important consideration when the materials are pharmaceuticalsor dyebearing mixes.

Having now described the invention, those skilled in this art will beable to make various changes and modifications without thereby departingfrom the scope and spirit of the invention as recited in the followingclaims.

lclaim:

1. Apparatus for mixing powdered or granular materials and automaticallydischarging the mixed materials in a continuous stream, said apparatuscomprising, I

a. an elongated, horizontally disposed tubular member having an outletopening at one end thereof,

b. a paddle wheel within the tubular member and extending substantiallythe full length of the tubular member,

c. power means for rotating the paddle wheel, and

d. means for vibrating the tubular member and paddle wheel in ahorizontal plane, the intensity of said vibrations being such as tofluidize the materials contained within the tubular member.

2. The invention as recited in claim 1, wherein the tubular member isclosed at the ends and has a semicircular bottom portion, wherein thesaid outlet opening is formed in an end wall of the tubular member atthe lower portion thereof, and wherein the paddle wheel is disposedwithin the semicircular bottom portion of the tubular member.

3. The invention as recited in claim 2, wherein the paddle wheelcomprises a plurality of axially spaced spiders secured to a first shaftrotatable in bearings carried by the end walls of the tubular member,and flat bars secured to the end portions of the spiders.

4. The invention as recited in claim 3, wherein the said tubular memberis secured to a supporting member vibrationally supported on a base;wherein the said power means for rotating the paddle wheel is a motorsecured to the said base and mechanically coupled to the said firstshaft; and wherein the said means for vibrating the tubular member andpaddle wheel are eccentric weights carried by a second shaft rotatablein bearings and driven by a second motor, the bearings for said secondshaft being carried by a rigid member secured to the said supportingmember and vibrationally isolated from the said base.

5. Apparatus for mixing powdered or granular materials comprising,

i a. abase,

b. an elongated tubular member having a semicircular bottom portionprovided with an outlet opening at one end thereof,

. means forming an inlet opening at the other end of the tubular member,

d. a first shaft extending through the tubular member and havingradially extending spiders secured thereto, said shaft beingsubstantially concentric with the said bottom portion of the tubularmember,

e. fiat bars secured to the end portions of said spiders,

f. means supporting the tubular member on said base, said meanspermitting axial vibration of the tubular member,

g. a rigid member secured to the tubular member and carrying bearings,said member being supported on the base by rubber-in-shear vibrationisolating means,

h. a second shaft rotatable in said bearings and carrying an eccentricweight,

i. a first motor carried by the said rigid member and having a driveshaft mechanically coupled to the said second shaft, and

j. a second motor carried by the base and having a drive shaftmechanically coupled to the said first shaft.

1. Apparatus for mixing powdered or granular materials and automaticallydischarging the mixed materials in a continuous stream, said apparatuscomprising, a. an elongated, horizontally disposed tubular member havingan outlet opening at one end thereof, b. a paddle wheel within thetubular member and extending substantially the full length of thetubular member, c. power means for rotating the paddle wheel, and d.means for vibrating the tubular member and paddle wheel in a horizontalplane, the intensity of said vibrations being such as to fluidize thematerials contained within the tubular member.
 2. The invention asrecited in claim 1, wherein the tubular member is closed at the ends andhas a semicircular bottom portion, wherein the said outlet opening isformed in an end wall of the tubular member at the lower portionthereof, and wherein the paddle wheel is disposed within thesemicircular bottom portion of the tubular member.
 3. The invention asrecited in claim 2, wherein the paddle wheel comprises a plurality ofaxially spaced spiders secured to a first shaft rotatable in bearingscarried by the end walls of the tubular member, and flat bars secured tothe end portions of the spiders.
 4. The invention as recited in claim 3,wherein the said tubular member is secured to a supporting membervibrationally supported on a base; wherein the said power means forrotating the paddle wheel is a motor secured to the said base andmechanically coupled to the said first shaft; and wherein the said meansfor vibrating the tubular member and paddle wheel are eccentric weightscarried by a second shaft rotatable in bearings and driven by a secondmotor, the bearings for said second shaft being carried by a rigidmember secured to the said supporting member and vibrationally isolatedfrom the said base.
 5. Apparatus for mixing powdered or granularmaterials comprising, a. a base, b. an elongated tubular member having asemicircular bottom portion provided with an outlet opening at one endthereof, c. means forming an inlet opening at the other end of thetubular member, d. a first shaft extending through the tubular memberand having radially extending spiders secured thereto, said shaft beingsubstantially concentric with the said bottom portion of the tubularmember, e. flat bars secured to the end portions of said spiders, f.means supporting the tubular member on said base, said means permittingaxial vibration of the tubular member, g. a rigid member secured to thetubular member and carrying bearings, said member being supported on thebase by rubber-in-shear vibration isolating means, h. a second shaftrotatable in said bearings and carrying an eccentric weight, i. a firstmotor carried by the said rigid member and having a drive shaftmechanically coupled to the said second shaft, and j. a second motorcarried by the base and having a drive shaft mechanically coupled to thesaid first shaft.